MC9S12E256 Datasheet, PDF (557/602 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 19 Module Mapping Control (MMCV4)
selected. In addition, the active-low emulation chip select signal, ECS, will likewise function based upon
the assigned memory allocation. In the cases of 48K byte and 64K byte allocated physical FLASH/ROM
space, the operation of the ECS signal will additionally depend upon the state of the ROMHM bit (see
Section 19.3.2.4, “Miscellaneous System Control Register (MISC)”) in the MISC register. Table 19-18,
Table 19-19, Table 19-20, and Table 19-21 summarize the functionality of these signals based upon the
allocated memory configuration. Again, this signal information is only available externally when the EMK
bit is set and the system is in an expanded mode.
Table 19-18. 0K Byte Physical FLASH/ROM Allocated
Address Space
Page Window Access
ROMHM ECS XAB19:14
0x0000–0x3FFF
N/A
0x4000–0x7FFF
N/A
0x8000–0xBFFF
N/A
0xC000–0xFFFF
N/A
N/A
1
0x3D
N/A
1
0x3E
N/A
0
PIX[5:0]
N/A
0
0x3F
Table 19-19. 16K Byte Physical FLASH/ROM Allocated
Address Space
0x0000–0x3FFF
0x4000–0x7FFF
0x8000–0xBFFF
0xC000–0xFFFF
Page Window Access
N/A
N/A
N/A
N/A
ROMHM
N/A
N/A
N/A
N/A
ECS
1
1
1
0
XAB19:14
0x3D
0x3E
PIX[5:0]
0x3F
Table 19-20. 48K Byte Physical FLASH/ROM Allocated
Address Space
0x0000–0x3FFF
0x4000–0x7FFF
0x8000–0xBFFF
0xC000–0xFFFF
Page Window Access
N/A
N/A
N/A
External
Internal
N/A
ROMHM
N/A
0
1
N/A
N/A
N/A
ECS
1
0
1
1
0
0
XAB19:14
0x3D
0x3E
PIX[5:0]
0x3F
Table 19-21. 64K Byte Physical FLASH/ROM Allocated
Address Space
0x0000–0x3FFF
0x4000–0x7FFF
0x8000–0xBFFF
0xC000–0xFFFF
Page Window Access
N/A
N/A
N/A
N/A
External
Internal
N/A
ROMHM
0
1
0
1
N/A
N/A
N/A
ECS
0
1
0
1
1
0
0
XAB19:14
0x3D
0x3E
PIX[5:0]
0x3F
MC9S12E256 Data Sheet, Rev. 1.08
Freescale Semiconductor
557